Electrically conductive polycarbonate-siloxane compositions

Patent metadata

Field	Value
Publication number	US-11118052-B2
Application number	US-202017128435-A
Country	US
Kind code	B2
Filing date	Dec 21, 2020
Priority date	Dec 31, 2019
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

Thermoplastic compositions include: (a) a thermoplastic polymer including a polycarbonate component; (b) a poly(carbonate-siloxane) copolymer; and (c) from 4 wt % to 25 wt % carbon black. The composition has a total siloxane content of from 2 wt % to 14 wt %. The thermoplastic compositions exhibit improved physical properties as compared to compositions that do not include the poly(carbonate-siloxane) copolymer, including volume resistivity, melt viscosity, impact strength, puncture impact energy and surface resistivity.

First claim

What is claimed is:

1. A thermoplastic composition comprising:
(a) a thermoplastic polymer comprising a polycarbonate component;
(b) a poly(carbonate-siloxane) copolymer; and
(c) from 8 wt % to 22 wt % carbon black,
wherein the composition has a total siloxane content of from 2 wt % to 14 wt %.

2. The thermoplastic composition according to claim 1 , wherein the poly(carbonate-siloxane) copolymer has a siloxane content of from 5 wt % to 25 wt %.

3. The thermoplastic composition according to claim 1 , wherein the polycarbonate component comprises a polycarbonate homopolymer, a polycarbonate copolymer that is different from the poly(carbonate-siloxane) copolymer in (b), or a combination thereof.

4. The thermoplastic composition according to claim 1 , wherein the carbon black is a structured carbon black having a BET nitrogen surface area of from about 65 square meters per gram (m 2 /g) to about 1500 m 2 /g as determined in accordance with ASTM D3037.

5. The thermoplastic composition according to claim 1 , wherein the composition has a volume resistivity of from 10 3 to 10 9 Ohm-centimeters (Ohm-cm) as determined in accordance with ASTM D257.

6. The thermoplastic composition according to claim 1 , wherein the composition has a melt viscosity at a shear rate of from 500 to 3000 l/second as determined in accordance with ASTM D3835 that is at least about 5% lower than that of a substantially identical reference thermoplastic composition that does not include a poly(carbonate-siloxane) copolymer.

7. The thermoplastic composition according to claim 1 , wherein the composition has a notched Izod impact strength at room temperature as determined in accordance with ASTM D256 that is at least about 100% higher than that of a substantially identical reference thermoplastic composition that does not include a poly(carbonate-siloxane) copolymer.

8. The thermoplastic composition according to claim 1 , wherein the composition has a notched Izod impact strength at −30 degrees Celsius (° C.) as determined in accordance with ASTM D256 that is at least about 40% higher than that of a substantially identical thermoplastic composition that does not include a poly(carbonate-siloxane) copolymer.

9. The thermoplastic composition according to claim 1 , wherein the composition has a puncture impact total energy at −30 degrees Celsius (° C.) as determined in accordance with ASTM D3763 that is at least about 50% higher than that of a substantially identical thermoplastic composition that does not include a poly(carbonate-siloxane) copolymer.

10. The thermoplastic composition according to claim 1 , wherein the composition has a surface resistivity as determined in accordance with ASTM D257 that is at least about 90% lower than that of a substantially identical thermoplastic composition that does not include a poly(carbonate-siloxane) copolymer.

11. The thermoplastic composition according to claim 1 , wherein the composition comprises from 10 wt % to 21 wt % carbon black and a total siloxane content of from 5 wt % to 12 wt %, and wherein the poly(carbonate-siloxane) copolymer has a siloxane content of from 5 wt % to 25 wt %.

12. The thermoplastic composition according to claim 1 , wherein the composition comprises from 13 wt % to 21 wt % carbon black and a total siloxane content of from 5 wt % to 12 wt %, and wherein the poly(carbonate-siloxane) copolymer has a siloxane content of from 5 wt % to 25 wt %.

13. An article comprising the thermoplastic composition according to claim 1 .

14. The article according to claim 13 , wherein the article is an electronic component.

Assignees

• Shpp Global Tech Bv

Inventors

• Silvi Norberto
• Kung Edward
• Vollenberg Peter
• Ziegler Christopher

Classifications

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C08L69/00 Primary

  Compositions of polycarbonates; Compositions of derivatives of polycarbonates · CPC title

• C08K2201/001

  Conductive additives · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C08G64/186

  containing polysiloxane sequences · CPC title